Aircraft



April 6,l 1937. J. v. GARDEN 2,076,398

AIRCRAFT Filed April 12, 1935 2 sheets-sheet 1` Gf-:N VALENTINE GARDEN INVENTOR "Simms/Mgg.

ATTORN5V5 April, 1937- J. v. GARDEN 2,076,398

l AIRCRAFT Filed April l2, 1935 2 Sheets-Sheet 2 y INVENTOR BMQM @e ATTORNEY5 `IOHN VALENTINE GARDEN Patented Apr. 6, 1937 UNITED STATES John Valentine Carden, Camberley, England Application April 12, 1935, Serial No,.15,985 In Great Britain April 18, 1934 3 Claims.

This invention relates to aircraft and more particularly. to the kind known as gliders or sailplanes.v It is common knowledge that a glider or sailplane. although capable of taking advantage of air currents to maintain its height when in the air, cannot rise from the ground Without external assistance and in order to give a glider sumcient impetus or iiying speed to rise from the ground.

' 'it is the usual practice either to towthe glider along the ground or to catapult it into the air by means of an elastic rope. If a prolonged flight is desired it is necessary either .tb launch the glider from a convenient hill or to tow the glider to a suitable height by means of an aeroplane.

Such arrangements have the disadvantages that several assistants are .required to get the machine Aair-borne and furthermore should the pilot Abe unable to maintain his height by soaring, it is often necessary for himto land at some distance 0 from the starting point the machine having then to be towed or otherwise conveyed back to the top of the hill or other starting point before a further flight can be made. The chief object of the invention is to overcome these disadvantages and to provide a glider or sailplane which is capable of rising from the groundgwithout external assistance but Awhich whenin theair will havethe same or substantially the same aerodynamic eiliciency as a glider 3Q or s ailplane of normal construction.

A glider or sailplane according to the invention is provided with power propulsion means for enabling it to rise from the ground into the air under its own power, 'said power propulsion means or a. part thereof being movable from its operative position, in which position it would oier considerable air resistance when the machine was in night, to an inoperative position/in vwhich position said power propulsion mean/s of`- fers a reducedor negative'air resistance/ The power propulsion means preferably takes the form of a small internal combustion engine driving an airscrew, the engine and airscrew preferably being normally contained within the contour of the glider when the latter is in flight, in

which position they offer little or no air resistance but adapted to be moved by the pilot into an operative and exposed position for such time as 4will enable tle glider to rise from the ground, l or if in flight for such time as will enable the machine to elect a landing at a desired point. Alternatively only a part of the power unit such as the air screw may be retractible, in which case the engine if fixed mayV either be built into the structure of the glider or if exposed, faired to offer the minimum of 'air resistance vwhilst in night.

In order that the said invention maybe clearly understoody and readily carried into veiect, the same will now be described more fully with ref erence to the accompanying drawings which illustrate a preferred embodiment of the invention wherein:-

Figure 1 is a fragmentary side elevation of the fuselage of a glider or sailplane showing the power unit in its inoperative or retracted position.

Figure 2 is a similar view showing the power unit in its alternative operative position.

Figure 3 is a rear elevation of Figure 1.

Figure 4 is a rear elevation of Figure 2. j

Figure`5` is a part sectional view of the. pre-4 -ferred mechanism `employed for moving the power unit into its retracted position.

Figure 6 is a transverse section to an enlarged scale on the line A-B in Figure 5.

In the construction of glider or sailplane illustrated the power unit includes a ysmall inverted single cylinder internal combustion engine I drivl Figure 2 to the inoperative position shown in Figure 1A in which latter position the airscrew, engine and its associated parts are housed within the fuselage or an upward extension thereof drectly behind the neck 4, and in thatposition offer no air resistance. The trailing edge of the wing is cut away as at 7 to permit of this pivotal movement of the engine, the engine being pro-v vided with a cowling 8 which when the engine is' in its retracted position fills up the opening in the trailing edge ofthe wing and constitutes a fairing for the upper part of the fuselage immediately behind the bulkhead 9 as shown in Figure l. The fairing is'completed by closure flaps I0 disposed on opposite sides of the fuselage and each formed in two sections hingedly connected together, the closure flaps being hingedly connected to the edges of the fuselage at l I and actuated-by bell crank levers l2 connected theretoand pivotally connected within the fuselage at the points I3. The closure flaps are adapted to be moved from the position shown in Figures 1 and 3 to the position shown in Figures 2 and 4 and vice versa by the vengagement of one of the blades Aof the airscrew with the extremities of the levers, thereby causing the levers to turn about their pivots and move the closure naps into the required position. The cowling is provided with an opening i4 for the ingress ,of air to maintain the engine at the correct temperature, the cowling at its upper end terminating in a small gravity y its retracted position it is essential that the airscrew should be stopped whilst in a vertical position and' although this may occur automatically on switching off the ignition due to the tendency l;V for the engine to stop with the piston at its bottom dead centre position (presumlng the airscrew to be in line .with the crank shaft and crank pin) means may be provided for turning the crank shaft by hand. Such means may take the form of a pawl and ratchet or similar device I6 associated with the end of the crank shaft and actuated by the vpilot through the medium of a hand lever situated within the cockpitand a flexible wire or vcable |8. The device may also be used for starting the engine from the pilots seat. Should difficulty be experienced in stopping the airscrew on switching off the ignition or closing the throttle a braking device may be provided operating on the crankshaft ora part associated therewith.

Any suitable means may be employed for moving the engine and its associated airscrew from its retracted position into Vits operative position and vice versa and in the construction illustrated the engine is adapted to be moved by means of a lifting strut I9 which serves to support the engine in its operative position. The strut I9 is pivotally connected to the engine at the point 2.0 and is pivotally connected at its lower end to trunnions 2| (see Figure 6) on a traversing nut 22 in screw threaded engagement with a threaded shaft 23. The shaft 23 is rotatably mounted in bearings 24 and 25 carried by the fuselage bulkheads 9 and 26 respectively. The trunnions 2| carry rollers 2'l running in channel shaped guides 28 alsocarried by the fuselage bulkheads. The shaft 23 projects at its forward end through the forward bulkhead `216 and carries a chain sprocket'wheel 29 rigidly secured thereon, the sprocket wheel 29 being connected by means of a chain 30 with a further sprocket wheel 3| secured to a countershaft 32 connected through the medium of bevel gears 33 with a rotatable handle 34 situated within the cockpit. By turning the handle in the appropriate direction the nut 22 is caused` to traverse the shaft 23, the engine and its associated airscrew being thereby moved into the required operative'or inoperative position. Any suitable form of engine mounting may be employed such as for example the rods 35 and 36 attached to the lower and upper ends of the engine respectively and serving to support the engine pivotally about the axis or point 6. With the arrangement of engine mounting illustrated 55 however the engine is so mounted that the position of its centre of gravity is substantially unchanged thereby preventing any change occurring in the trim of the machine due to moving the engine from its operative to its inoperative 60 position and vice versa.

It will be apparent from the foregoing description that a glider or sailplane fitted with an aux- A iliary power unit according to the invention will when once in the air have substantially the aero- 65 dynamic eiiiciency of a glider or sailplane of normal construction, due to the streamlined contour of the glider being unimpaired when the power unit 1;: inits inoperative position. In order to facilitate the glider rising from the ground the 70 fuselage may be provided with relatively small and light landing wheels instead of the usual skid, the landing .wheels if necessary being retractible into the fuselage to decrease still further the air resistance. 75 Instead of the pivotal method of mounting the power unit, the power unit, or. a part thereof. such as, for example the airscrew, may be mounted in any other desired way which will enable it to be slidden or otherwise moved into an inoperati'vev position, in which position it offers a dlminished air resistance.

What I claim and desire to secure by Letters Patent of the United States is:-

l. A glider or sailplane having as its sole power propulsion means adapted for use or withdrawal at will an auxiliary power propulsion unit in the upper portion of the fuselage of said glider in the form of a small engine and an airscrew in driving connection therewith, there being a cowling on said enginefsaid propulsion unit when in its operative position occupying an exposed position upon said upper portion of the fuselage in which it lies outside and above the contour of the structure of the glider, and there being a recess in the upper surface of said fuselage and said cowling, and means for moving and lowering the whole of said propulsion unit into an inoperative withdrawn position in which the airscrew lies within said recess in the upper surface -of the fuselage and said cowling, and reduces the entire plane structure substantially to the proportions and outline of a mere glider, there being pivoted iiaps on said fuselage for closing said recess.

2. A glider or sailplane having as its sole power propulsion means adapted for use or withdrawal at will an auxiliary power propulsion unit in the upper portion of the fuselage of said glider in the form' of a small engine and an airscrew in the form of a small engine and an airscrew in driving connection therewith, said propulsion unit when in its operative position occupying an exposed position upon said upper portion ofthe fuselage in which it lies outside and above the contour of the structure of the glider, there being a recess in the upper surface of the fuselage of the glider, means for moving and lowering the whole of said propulsion unit into an inoperative withdrawn position .in which position the airscrew lies within said recess in said upper surface of the'fuselage, a cowling on'said engine and there being pivoted flaps on said fuselage for closing said recess, said pivoted flaps and the air propulsion unit in withdrawn position serving to reduce the entire plane structure substantially tol the proportions and outline of a mere glider, and means operable by said airscrew to move said ap vto,ar1d from their operative positions to cover and uncover said recess. Y

3. A glider or sailplane having as its sol`e power propulsion means adapted for use or withdrawal at will an auxiliary power propulsion unit in the upper portion of the fuselage of said glider in the form of a small engine and an airscrew in driving connection therewith, there being a cowling on said engine, said propulsion unit when in its operative position occupying an exposed position upon said upper portion of the fuselage in which it lies outside and above the contour of the structure of the glider, and there being a recess in the upper surface of said fuselage and said cowling, and means for moving and lowering the whole of said propulsion unit into an inoperative withdrawn position in which the propulsion unit including the airscrew lies within said recess in the upper surface and within the outline of the fuselage and said cowling, and reduces the entire plane structure substantially to the proportions outline of a mere glider.

JOHN VALENTINE GARDEN. 

